Proportioning drafting instrument



T. J. 50TH ,July 29, 1930,

PROPORT IONI NG DRAFT ING INS TRUMEIiT Filed Jan. 20,1928

INVENTOR lzomw'J 5o BY M ;ATTORNEY Patented July 29, 1930 cairn STATSPATENT THOMAS J. some, or BROOKLYN, NEW YORK PROPbRTIONING DRAFTINGINSTRUMENT Application filed January 20, 1928.

This invention relates to a new and useful device inthe nature of adrafting instrument especially adapted for the purpose of providing ameans of assisting in the drafting or drawing of objects, scenery, mapsand the like,

and particularly perspective drawings.

The object of the invention is to provide a device of the classdescribed of novel construction and arrangement of parts, embodyingcertain adjustable features hereinafter 20 bodied in my improved device.

Fig. 4: is a similar view to that shown in Fig. 3 illustrating anotherform of the drawing frame.

Fig. 5 is a transverse sectional view taken 25 On the line 5-5 of Fig.4.

As here embodied my improved device co1nprises a standard 10, or supportwith a base element 11, of suitable size and weight to support myimproved device. The stando ard is vertically disposed and is providelwith an enlarged extended extremity 1.2, having formed therein ahorizontal aperture adapted to slidably receive the rod 13, as a meansof horizontally supporting the rod 35 13. The thumb screw 14 isthreadedly formed therein a central aperture 18. The thumb screw 19 isthreadedly mounted in the enlarged extremity 15 of the rod 13, and isadapted to frictionally engage the stem 16 of 50 the said sight, as ameans of holding the said The sight 4 5 17 is of circular convexconstruction, having Serial No. 248,039.

sight in any desired vertically extendedposition. .1 y

The drawing frame 20 isof rectangular frame like construction and isadapted to .frictionally engage in an opening 21 formed 5 in the support22,0f block shapeconstruc- ,tion, having formed therein an apertureadapted to slidably engage on the above mentioned rod 13. The thumbscrew 23 is threadedly mounted in the support 22and isadapted tofrictionally engage the rod 13, as a means of holding the drawing frame20 in any desired verticallyextended position in the said rod. Thedrawing frame 20 has formed therein apertures 24, 25 and 26-, 27-positioned or located at the top and bottom and at the twosidesthereof,respectively.

The'fiexible member 28,thread, string,'-cord or the like, is threaded orpassed through the said apertures formed in the drawing 7 frame 20, soas to provide transverseand longitudinal members 29 and 30 extendedacross the opening formed in the said drawing frame. I. v

My improved device is 'used as follows;- the drawing frame supported asabove set forth in place in frontof the object desired to be drawn, theperson making the drawing looks through theaperture formed=in-the sightfor. the purpose of permitting the said transverse andlongitudinalmembers extended across the opening formed in the draw ingframe toprovide guide lines which will obviously assist in the drawingof the said object.

In Fig. 2 of the accompanyingdrawing, I have shown a layout frame 31, ofrectangular frame shape construction, having formed therein apertures32, 33, 3 1 and formed in the top, bottom and sides, respectivelythereof. The above described construction is such as will permit thelayout frame to be placed on the piece of paper upon which the abovementioned drawing is to be made, and a pencil point inserted through,for the purpose of'providin'g guide dots on the said piece of paperwhich will permit transverse and longitudinal lines to be drawn on thesaid piece of paper, which will obviously assist in the drawing of thesaid object on the paper.

, respectively of the said drawing frame. said clamp members 45 and 46are provided In Figs. 4 and 5, I have shown a drawing frame 36,substantially of rectangular frame shaped construction, provided with anare shaped side 37, formed at a radius from the pin 38, secured to andextended from the opposite side of the said drawing frame 36, andprovided with a similar are shaped top 39, formedat a radius from thepin-40, se cured to and extended from the bottom of the said drawingframe. The flexible members 41 and 42 are secured respectively, to thepins 38 and 40, and are extended therefrom' and are secured respectivelyto the extended elements 43 and 44, respectively, of the clamp members45 and 46, provided with lower ex- -tended elements 47 and:48, adaptedto frictionally engage the arc shape side and top, The

respectively with handle elements49. and 50,

-as aimeans of slidahly positioning the said .or reproduction, ofobjectsnin perspective.

clamp members as may be desired, and designatedby the reference numerals51, 52, 53 and 54, respectively.

The drawing frame has aflixed thereto, graduation marks 55 and 56 withaccompanying and corresponding devgreesaffixed thereto, as a means ofdesignating the angularity of the said flexible members; The abovedescribed construction is such as-wlll obviously assist in the drawingHaving thus described my invention,what

" I. claim as new and desire-to protect by Uni-ted States Letters Patentis In a drafting: instrument of the class de- ,scribed,.a drawingframeprovided with an arcuate side and top, a cordsecured at one end on thebottom ofthe frame and at. the center of curvature of said arcuate top,a

secondcord secured at one end on the side of .theframe opposlte thesaldarcuate side at the center ofcurvature of said side, clamp 7 membersslidably mounted on thearcuate top ,and side of-said-frame, andth'eother ends of-the cords being attached on'the clamp.members,respectively for providing guide lines. 7

In testimony whereof I have affixed my THOMAS J. SOTH.

; signature.

